Recently, vehicles such as, for example, a hybrid car or an electric car that uses an electric motor as a driving source are being distributed widely. These vehicles tend to be quiet while running on the road as compared to gasoline vehicles. Particularly, the running sound of the vehicles is very quiet when driven at a low speed. Thus, there exists a problem in that other vehicles and pedestrians have difficulty in noticing these vehicles approaching from the outside of the field of vision such as, for example, from the rear side.
To solve such a problem, a technology is being developed which notifies the proximity of the vehicle by generating a pseudo engine sound separately from a motor sound. For example, Japanese Application Laid-Open No. 2007-283809 discloses a device provided with a vibrator in the inside of a headlight cover.